This paper discusses the introduction of electric power in the city of São Paulo during the beginning of the 20th century. The Brazilian Republic Proclamation (1889) established the beginning of the public services companies' modernization, which through the enterprises fusion and the arrival of foreign capital allowed the electric power introduction in the main Brazilian cities. Two rival groups started a competition in the São Paulo's electric sector: the national enterprise Companhia Brasileira de Energia Elétrica (CBEE) - so called as Docas de Santos - and the Canadian company Light. The inexistence of a federal legislation to electric power services had transformed municipal decisions in deterministic guidelines for utility bids, making municipal lobbying a key instrument in utility concessions. Hence, this paper issues describe the electric power introduction in the city through the debates about the utilities' rules, analyzing the political or ideological criteria that build the São Paulo's laws for electricity sector.